<div class="container">
	<div class="box"/>
</div>
<style>
.container{
	position:relative;
	height:30px;
}
.box{
	position:absolute;
	left:0;
	height:30px;
	width:30px;
	background-color:hsl(130,50%,50%);
	transition:all 1s linear;
}
.container:hover .box{
	left:400px;
}
</style>